Dead heading annuals

[MissMarplesNiece]

I've got Bizzy Lizzies growing in pots. Do I need to dead head them?

you'll usually get a longer flowering period if you do. Setting seed takes energy and the plant ‘thinks’ its job is done.
But if you’ve got kids I’d let a few seed pods develop on a Busy Lizzie so they can ‘explode’ them.